probleme curseurs

Please Consider including the following in your question:

• Adobe product and version number
• Operating system and version number
• The full text of any error message (s)
• What you were doing when the problem occurred
• Screenshots of the problem
• Computer hardware, such as CPU; GPU; the amount of RAM; etc

What has been changed on yur system before the error occur?

Do you have restart your computer?

What you can try first is resetting the preferences of Lightroom Classic:   https://helpx.adobe.com/lightroom-classic/help/setting-preferences-lightroom.html

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html